
Description
The speed of light in a material is c/2. What is the critical angle of a light ray at the interface between this material and a vacuum?
A. 32 degrees
B. 24 degrees
C. 30 degrees
D. 27 degrees
E. 21 degrees

The speed of light in a material is c/2. What is the critical angle of a light ray at the interface between this material and a vacuum?
A. 32 degrees
B. 24 degrees
C. 30 degrees
D. 27 degrees
E. 21 degrees